DESCRIPTION: (Applicant's Abstract) This proposal responds to the National Institute on Drug Abuse's Program Announcement, PA-95-027, of February 3, 1995, on the linkage of drug abuse treatment and medical care. Although the prevalence of medical problems among substance abuse patients is known to be extensive, a question remains of what is the cost and effectiveness, both in terms of substance abuse and medical outcomes, of providing primary medical care in the context of structured outpatient drug abuse treatment. Specifically, this proposal describes a controlled, random assignment comparison of two treatment conditions among 650 substance dependent patients (34% women, 13% African American, and 10% Hispanic) treated in the substance abuse program of a large health maintenance organization (HMO). The two conditions are 1) "integrated" services, where patients receive all their primary health care from medical personnel within the substance abuse unit itself; and 2) an "independent," treatment as usual group, where patients receive their primary health care and drug abuse treatment services independently at different sites; these substance abuse patients receive their primary health care through the regular HMO clinics. The study compares the effects of these two models of service delivery during the course of drug abuse treatment, measuring treatment engagement, length of stay, and drug use. It also compares post treatment outcome and improvement rates in the areas of substance use, medical status, levels of psychosocial functioning, and medical care utilization between the two conditions, and it attempts to specify patient characteristics associated with successful treatment outcomes. Finally, it compares the costs of the Integrated and Independent (treatment as usual) conditions, and assesses cost effectiveness of the two sets of service arrangements. The HMO setting is an important "real world" environment in which to conduct such a study; it has a heterogeneous patient population, and such managed care settings are increasingly becoming a predominant form of service delivery.